The present invention relates generally to communication technology and specifically to a piezoelectric signal generator, i.e. a device which uses a piezoelectric element to activate an emitter for generating an electromagnetic signal. Various such devices have been suggested in the art, e.g. in U.S. Pat. Nos. 4,612,472, 6,630,894, DE 2 314 420, DE 2 939 440 and EP 1 217 742.
Such devices include at least one piezoelectric element which is connected with an emitter such that a current produced by the piezoelectric element will actuate the emitter and cause it to generate and send an electromagnetic signal to a receiver which is removed from the emitter. Depending upon the specific needs, the wavelength of the electromagnetic signal may be in the visible range or in the radio frequency range, e.g. in the ultra short wave range, and the distance between the emitter and the receiver may vary between a few centimetres and many meters or even kilometres.
However, few such products, if any, have lead to commercially viable products and most prior art disclosures do not specify the nature of the piezoelectric element that is postulated to be capable of actuating the emitter. When specifics about the piezoelectric element are given, such as in EP 1 217 742, commercially available bimorphs in the form of bending strips are suggested to provide for sufficient electrical energy, typically in the range of several mJ (millijoule; equivalent to mV·sec). Substantial deformation of such a piezoelectric element is required for actuation of the emitter and is, of course, detrimental to the useful life of a device so constructed.